A combined determination method and system for prestressing of in-service slope anchor cables

Abstract

The present invention relates to the technical field of geological disaster prevention and control, and in particular, to a combined determination method and system for prestress of in-service slope anchor cables. The method comprises selecting at least three groups of anchor cables, performing echo signal determination, extracting discrete data of different wave reflection time periods, calculating the echo energy corresponding to at least three groups of anchor cables, determining the prestress of the anchor cables by a back-pulling method, constructing a fitting function based on the echo energy and the prestress, and realizing the calculation of the prestress based on the echo signal of the anchor cable to be tested and the fitting function. Compared with the existing detection methods, the method adopts a non-destructive detection method to complete most of the workload, the used instruments and equipment are light, the detection process is simple, the detection efficiency is significantly improved, and there is no potential harm to the structure.

Description

Technical Field

[0001] The present invention relates to the technical field of geological disaster prevention and control, and in particular to a combined determination method and system for prestress of in-service slope anchor cables. Background Art

[0002] In order to achieve the smooth operation of the anchoring project and accurately grasp the prestress value of the anchor cable, in the existing technology, the long-term data of the structure with embedded sensors is obtained by using monitoring equipment. However, in some projects, the structure without embedded sensors is often detected by the reverse pull method, which is mainly based on the load-displacement curve to determine the prestress. This method has high accuracy, but the process is cumbersome, time-consuming and labor-intensive, and may damage the existing structure, and is not "non-destructive". In addition, the reverse pull method requires the use of supporting tensioning equipment and clamping devices. The overall process is cumbersome and laborious, especially on steep slopes. The transportation of instruments and equipment is extremely inconvenient, and the exposed steel strands of some anchor cables are short, which further increases the difficulty of detection by this method. In addition, the slope anchor cables are densely distributed, especially on the slopes of major projects. The number of anchor cables is as many as thousands of bundles, and it is difficult to implement the traditional reverse pull method to detect each bundle one by one. Therefore, for a large number of slope anchor cables, how to safely, conveniently and efficiently detect their prestress values ​​is a technical problem that needs to be solved urgently.

[0003] In view of this, this application is hereby filed. Summary of the invention

[0004] In response to the above problems, an embodiment of the present invention provides a combined determination method and system for the prestress of in-service slope anchor cables. Compared with existing detection methods, this method uses non-destructive testing methods to complete most of the workload. The instruments and equipment used are lightweight and the detection process is simple, which significantly improves the detection efficiency and has no potential harm to the structure.

[0005] The present invention is achieved through the following technical solutions:

[0006] First aspect

[0007] The embodiment of the present invention provides a combined determination method of prestress of an in-service slope anchor cable, comprising the following steps:

[0008] S1: Select at least three groups of anchor cables, measure the echo signals, extract the discrete data of different wave reflection periods, and calculate the echo energy corresponding to at least three groups of anchor cables. , where E is the echo energy (sound energy); n1 is the starting time of calculation; n2 is the end time of calculation; x[n] is the amplitude;

[0009] S2: For at least three groups of anchor cables selected in step S1, the prestress of the anchor cables is determined by the reverse tension method. F ;

[0010] S3: Based on at least three groups of echo energies E and at least three groups of prestressing forces obtained in step S1 and step S2 F， Construct a fitting function, where the fitting function is , the fitting parameters a, b, c are calculated based on steps S1 and S2;

[0011] S4: Determine the echo signals of other anchor cables to be inspected, and calculate the prestress based on the echo signals of the anchor cables to be inspected and the fitting function.

[0012] In this scheme, the method constructs a fitting function for prestress measurement by performing nondestructive testing and back-pull method on at least three groups of anchor cables, and calculates prestress by performing nondestructive testing on the anchor cables to be tested and combining the echo energy of the nondestructive testing with the fitting function. Compared with the existing detection methods, this method uses nondestructive testing methods to complete most of the workload. The instruments and equipment used are light and the detection process is simple, which significantly improves the detection efficiency and has no potential harm to the structure.

[0013] Furthermore, a pretreatment step is included before step S1, and the pretreatment step includes opening the outer anchor head protection cover and cleaning the surface of the anchor plate.

[0014] Furthermore, in step S1, the selected at least three groups of anchor cables should meet the requirements of the same specification and model and be located in the same slope.

[0015] Furthermore, the anchor points of at least three groups of anchor cables are selected to be set close to the traffic channel.

[0016] Furthermore, in step S1, the following steps are specifically included:

[0017] S11: fix the action position of the probe and apply the probe vertically to the surface of the anchor plate;

[0018] S12: Excite and receive echo signals through a pulse transmitter and receiver, use an oscilloscope to display the waveform and transmit the result to a computer;

[0019] S13: Extract discrete data at different reflection time periods and automatically calculate echo energy .

[0020] Furthermore, in step S11, the probe is a magnetic probe.

[0021] Furthermore, in step S12, the probe action position is adjusted multiple times and echo signal collection is performed.

[0022] Furthermore, in step S13, data of the tail wave segment in the echo is extracted for calculation.

[0023] Second aspect

[0024] An embodiment of the present invention also provides a joint determination system for the prestress of in-service slope anchor cables, including an acquisition module: a first acquisition module for acquiring echo signals of anchor cables and a second acquisition module for acquiring prestress based on a back-pull method; a processing module: the processing module is used to extract discrete data of different wave reflection time periods according to the echo signals, and to calculate echo energy; to construct fitting parameters based on prestress and echo energy; and to calculate the prestress of the anchor cables to be tested based on the fitting parameters and the echo signals of the anchor cables to be tested.

[0025] The third aspect

[0026] An embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps of the above method are implemented.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] The embodiment of the present invention provides a method and system for jointly measuring the prestress of in-service slope anchor cables. The method constructs a fitting function for prestress measurement by performing nondestructive testing and back-pull method testing on at least three groups of anchor cables, and calculates the prestress by performing nondestructive testing on the anchor cables to be tested and combining the echo energy of the nondestructive testing and the fitting function. Compared with the existing testing methods, the method uses nondestructive testing methods to complete most of the workload, the instruments and equipment used are light, the testing process is simple, the testing efficiency is significantly improved, and there is no potential harm to the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative work:

[0030] Figure 1 A flow chart of a combined determination method of prestress of an in-service slope anchor cable provided by an embodiment of the present invention;

[0031] Figure 2 A schematic diagram of a structure for performing echo energy collection provided by an embodiment of the present invention;

[0032] Figure 3 A schematic diagram of a structure using the reverse pull method for measurement provided in an embodiment of the present invention;

[0033] Figure 4 A waveform diagram obtained by echo acquisition provided by an embodiment of the present invention.

[0034] Marks and corresponding parts names in the attached drawings:

[0035] 110 - first acquisition module, 120 - second acquisition module, 200 - processing module. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0037] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is apparent to one of ordinary skill in the art that these specific details are not necessarily employed to practice the present invention. In other instances, well-known structures, circuits, materials, or methods are not specifically described in order to avoid obscuring the present invention.

[0038] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment," "an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. In addition, it will be appreciated by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0039] In the description of the present invention, it should be understood that the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the scope of protection of the present invention.

[0040] Example

[0041] like Figure 1 As shown, an embodiment of the present invention provides a combined determination method of prestress of an in-service slope anchor cable, comprising the following steps:

[0042] S1: Select at least three groups of anchor cables, measure the echo signals, extract the discrete data of different wave reflection periods, and calculate the echo energy corresponding to at least three groups of anchor cables. , where E is the echo energy (sound energy); n1 is the starting time of calculation; n2 is the end time of calculation; x[n] is the amplitude;

[0043] S2: For at least three groups of anchor cables selected in step S1, the prestress of the anchor cables is determined by the reverse tension method. F ;

[0044] S3: Based on at least three groups of echo energies E and at least three groups of prestressing forces obtained in step S1 and step S2 F， Construct a fitting function, where the fitting function is , the fitting parameters a, b, c are calculated based on steps S1 and S2;

[0045] S4: Determine the echo signals of other anchor cables to be inspected, and calculate the prestress based on the echo signals of the anchor cables to be inspected and the fitting function.

[0046] In this scheme, the method constructs a fitting function for prestress measurement by performing nondestructive testing and back-pull method on at least three groups of anchor cables, and calculates prestress by performing nondestructive testing on the anchor cables to be tested and combining the echo energy of the nondestructive testing with the fitting function. Compared with the existing detection methods, this method uses nondestructive testing methods to complete most of the workload. The instruments and equipment used are light and the detection process is simple, which significantly improves the detection efficiency and has no potential harm to the structure.

[0047] In some embodiments, a pretreatment step is further included before step S1, and the pretreatment step includes opening the outer anchor head protection cover and cleaning the surface of the anchor plate.

[0048] Specifically, cleaning the surface of the anchor plate through the pretreatment step can ensure the stability of the cooperation between the probe and the surface of the anchor plate, thereby ensuring the accuracy of the measurement.

[0049] In some embodiments, in step S1, the selected at least three groups of anchor cables should meet the requirements of the same specification and model and be located in the same slope.

[0050] In some embodiments, the anchor points of at least three selected groups of anchor cables are arranged close to the traffic channel.

[0051] Specifically, as technical personnel in this field should know, different specifications and models of anchor cables obtain different fitting parameters. By targeting the same specifications and models, the accuracy of the fitting function is guaranteed, and through position selection, considering that the equipment used in the reverse pull method is heavy, the convenience of measurement using the reverse pull method can be guaranteed.

[0052] In some embodiments, step S1 specifically includes the following steps:

[0053] S11: fix the action position of the probe and apply the probe vertically to the surface of the anchor plate;

[0054] S12: Excite and receive echo signals through a pulse transmitter and receiver, use an oscilloscope to display the waveform and transmit the result to a computer;

[0055] S13: Extract discrete data at different reflection time periods and automatically calculate echo energy .

[0056] In some embodiments, in step S11, the probe is a magnetic probe.

[0057] Specifically, the use of a magnetic probe can ensure that the force between the magnetic probe and the anchor plate is relatively stable.

[0058] Furthermore, in order to ensure sufficient contact between the probe and the anchor plate, the diameter of the probe is between 5 and 15 mm.

[0059] In some embodiments, in step S12, the probe action position is adjusted multiple times and echo signal acquisition is performed.

[0060] Specifically, the data is collected at multiple locations, and the average value of the collected signals is taken to calculate the result, so as to improve the detection accuracy.

[0061] In some embodiments, in step S13, data of the tail wave segment in the echo is extracted for calculation.

[0062] Specifically, extracting the tail wave data in the echo for calculation can better reflect the differences in waveform characteristics corresponding to different prestresses and further improve the detection accuracy.

[0063] like Figure 2-3 As shown, an embodiment of the present invention further provides a joint determination system for prestress of in-service slope anchor cables, including an acquisition module: a first acquisition module 110 for acquiring echo signals of anchor cables and a second acquisition module 120 for acquiring prestress based on a back-pull method; a processing module: the processing module is used to extract discrete data of different wave reflection time periods according to the echo signals, and to calculate echo energy; to construct fitting parameters based on prestress and echo energy; and to calculate the prestress of the anchor cables to be tested based on the fitting parameters and the echo signals of the anchor cables to be tested.

[0064] An embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps of the above method are implemented.

[0065] In the embodiments of the present invention, the processor may be an integrated circuit chip having the ability to process signals. The processor may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0066] The methods, steps and logic block diagrams disclosed in the embodiments of the present invention can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiments of the present invention can be directly embodied as a hardware decoding processor for execution, or can be executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The processor reads the information in the storage medium and completes the steps of the above method in combination with its hardware.

[0067] In a specific embodiment, determination is made for YJM15-4:

[0068] S1: Select three YJM15-4 anchor cables at the measurement site, open the outer anchor head protection cover, and use a clean rag to remove debris on the surface of the anchor plate;

[0069] S2: Put the hoop on the anchor plate, adjust its position so that its center is aligned with the center of the anchor plate, and fix it with fixing bolts;

[0070] S3: Install the probe position fixing device (including the slider, slider fixing bolts, guide rod, positioning rod, transmission wire, and reading instrument) on the hoop slide rail;

[0071] S4: Adjust the position of the slider and the positioning rod so that the center of the positioning ring is placed on the symmetry line of the anchor plate between the anchor holes;

[0072] S5: Connect the magnetic probe to the pulse transmitter and receiver through a first data line, connect the pulse transmitter and receiver to the oscilloscope through a second data line, and connect the oscilloscope to the computer through a third data line;

[0073] S6: Apply coupling agent to the bottom of the magnetic probe and place it in the positioning ring;

[0074] S7: Collect the echo signal, and the obtained waveform is as follows Figure 4 As shown;

[0075] S8: Extract discrete data (sound pressure) between 50.9μs and 53.9μs, as shown in the following table;

[0076]

[0077] S9: Using formula , calculate the echo energy value E1=5.707 at this measuring point;

[0078] S10: repeat the above S2 to S9, change the action position of the probe, and obtain the echo energy values ​​E1 to E8 at the 2nd to 8th positions;

[0079] S11: Calculate the average value E of E1~E8 p1 , which is taken as the result of the first anchor cable measurement;

[0080] S12: Repeat S2 to S11 to obtain the echo energy values ​​E of the second and third anchor cables respectively. p2 、E p3 ;

[0081] S13: using the reverse tension method, respectively measure the prestress values ​​F1, F2, and F3 of the first, second, and third anchor cables;

[0082] S14: According to the system of equations , calculate the fitting parameters a, b, c;

[0083] S15: Open the outer anchor head protection cover of other anchor cables to be tested, remove the debris on the surface of the anchor plate with a clean rag, repeat S2 to S11 above, and obtain the echo energy value E at this location. pi ;

[0084] S16: Adoption , calculate the prestress value of the anchor cable at this location.

[0085] S17: Restore the outer anchor head protection cover and end the inspection.

[0086] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific implementation methods of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A combined determination method for prestressing of in-service slope anchor cables, characterized in that: The steps include: S1: Select at least three groups of anchor cables, measure the echo signals, extract the discrete data of different wave reflection periods, and calculate the echo energy corresponding to at least three groups of anchor cables. Where E is the echo energy; n1 is the starting time of calculation; n2 is the end time of calculation; x[n] is the amplitude; S2: for at least three groups of anchor cables selected in step S1, the prestress F of the anchor cables is measured by a reverse tension method; S3: Based on at least three groups of echo energies E and at least three groups of prestress F obtained in step S1 and step S2, a fitting function is constructed, wherein the fitting function is The fitting parameters a, b, c are calculated based on steps S1 and S2; S4: Determine the echo signals of other anchor cables to be inspected, and calculate the prestress based on the echo signals of the anchor cables to be inspected and the fitting function.

2. A combined determination method for prestressing of in-service slope anchor cables according to claim 1, characterized in that: Before step S1, a pretreatment step is also included, and the pretreatment step includes opening the outer anchor head protection cover and cleaning the surface of the anchor plate.

3. A combined determination method of prestress of in-service slope anchor cables according to claim 1, characterized in that: In step S1, the selected at least three groups of anchor cables should meet the requirements of the same specification and model and be located in the same slope.

4. A combined determination method of prestress of in-service slope anchor cables according to claim 3, characterized in that: The anchor points of at least three groups of anchor cables are selected and set close to the traffic channel.

5. The combined determination method of prestress of in-service slope anchor cables according to claim 1 is characterized in that: In step S1, the following steps are specifically included: S11: fix the action position of the probe and apply the probe vertically to the surface of the anchor plate; S12: exciting and receiving echo signals through a pulse transmitter and receiver, displaying waveforms using an oscilloscope and transmitting the results to a computer; S13: Extract discrete data at different reflection time periods and automatically calculate echo energy 6. A combined determination method of prestress of in-service slope anchor cables according to claim 5, characterized in that: In step S11, the probe is a magnetic probe.

7. A combined determination method for prestressing of in-service slope anchor cables according to claim 5, characterized in that: In step S12, the probe action position is adjusted multiple times and echo signal collection is performed.

8. A combined determination method for prestressing of in-service slope anchor cables according to claim 5, characterized in that: In step S13, data of the tail band in the echo is extracted and calculated.

9. A combined determination system for prestress of in-service slope anchor cables, based on a combined determination method for prestress of in-service slope anchor cables as claimed in any one of claims 1 to 8, characterized in that: include: Acquisition module: the acquisition module is used for collecting the first acquisition module of the echo signal of the anchor cable and the second acquisition module for realizing prestress acquisition based on the back-pull method; Processing module: The processing module is used to extract discrete data of different wave reflection periods according to the echo signal and calculate the echo energy; and to construct fitting parameters based on the prestress and the echo energy; Based on the fitting parameters and the echo signal of the anchor cable to be tested, the prestress calculation of the anchor cable to be tested is realized.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method described in any one of claims 1 to 8 are implemented.

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